Method for detecting moisture on a road surface

Abstract

In a method for detecting moisture on a road surface used by a vehicle, wherein at least one acoustic signal resulting from the moisture on the road surface is captured by at least one sensor device arranged on said vehicle, and wherein the captured acoustic signal is analysed via at least one analyser associated with said vehicle, it is provided according to the invention that at least one energy value of at least one signal portion of the captured acoustic signal is calculated for the analysis, that the effective value of the at least one signal portion is calculated, that a shape factor of the at least one signal portion is calculated from the quotient of the effective value and the energy value, that the minimum of the energy value in the at least one signal portion is calculated, that the maximum of the shape factor in the at least one signal portion is determined, that a quotient of the minimum of the energy value and the maximum of the shape factor is created and that said quotient is associated with a degree of wetness of the road surface.

Description

BACKGROUND OF THE INVENTIONField of the Invention[0001]The invention relates to a method for detecting moisture on a road surface, wherein at least one sound signal caused by the moisture on said road surface is captured by at least one sensor device, and wherein the captured sound signal is analysed via at least one evaluation device.Brief Discussion of the Related Art[0002]Methods for detecting moisture or wetness on a road surface are known particularly in the automotive sector. The detection of a degree of wetting of a road surface specifically is required to issue alerts to the vehicle user, such as regarding the risk of aquaplaning. Furthermore, vehicle safety systems can be pre-conditioned by analysing the degree of wetting of the road surface to facilitate a faster triggering of the vehicle safety systems.[0003]Sound sensors, in particular structure borne sound sensors, are an example of sensors that can be used for detecting the moisture on a road surface. Specifically, str...

AI Technical Summary

Benefits of technology

[0018]In a further development of the invention, the sound signal is a structure borne sound signal. Capturing the structure borne sound signal via structure borne sound sensors, in particular in an area of the exterior surface of the vehicle, onto which water spray is dispersed by the tyres, facilitates the easy detection of moisture on a road surface used by the vehicle.

[0019]In a further development of the invention, the captured sound signal is filtered via a high-pass filter prior to the calculation of the energy values. The high-pass filter suppresses frequency portions of a captured signal, which lie below a cut-off frequency. For example, frequency portions can be suppressed, which are caused by vibrations resulting from the air stream or other vibrations associated with driving operations. This facilitates the analysis of the frequency portions, which are caused

Problems solved by technology

This makes it more difficult to detect low degrees of wetting of the road surface, as a sma

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